1. Field of the Invention
The present invention relates to a hybrid vehicle drive control system of a hybrid vehicle having an electric drive (EV) mode a hybrid drive (HEV) mode. More particularly, the present invention relates to a hybrid vehicle drive control system for starting an engine of a hybrid vehicle having a first clutch is interposed between the engine and a motor/generator, and a second clutch is interposed between the motor/generator and a drive wheel, with one of a plurality of clutches disposed within a transmission being used as the second clutch.
2. Background Information
Various configurations have been proposed for hybrid vehicle drive systems used in such hybrid vehicles. In hybrid vehicle, an engine and a motor/generator are used to provide a driving force to one or more drive wheels. A hybrid vehicle equipped with a hybrid vehicle drive control system can be put into an electric drive (EV) mode in which the vehicle travels solely by means of power from the motor/generator. Such a hybrid vehicle can also be put into a hybrid drive (HEV) mode in which the vehicle travels using power from both the engine and the motor/generator. In the electric drive (EV) mode, the engine is stopped when it is not needed and then started when it is determined to be needed, according to prescribed vehicle operating conditions. Typically, with most vehicles, the engine is idle when the vehicle is stationary. When the engine is engaged to transmit power, a control is performed for varying the capacity of the torque converter, with the clutches in the transmission being in completely engaged conditions. One example of such a drive control system is disclosed in Japanese Laid-Open Patent Publication No. 2003-004138.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved hybrid vehicle drive control system. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.